when I write this $thread = Thread::find($id); then I write {{$thread->title}} it gives me the title of the thread, but when I write $thread = Thread::where('id','=',$id); then I write {{$thread->title}} it gives me an error.why is that happening?
You should write:
$thread = Thread::where('id','=',$id)->first();
to get one column, else laravel will understand it as array.
You need to call the get() (or any of its variants) method to execute the actual query when using where.
Thread::where('id','=',$id)->get();
Otherwise Thread::where('id','=',$id) just gets you an instance of eloquent's query builder.
find() on the other hand will automatically run a query for whatever it is you want to find by you can't do all sorts of useful stuff (e.g. orderBy, paginate, etc.) that you can very easily pull of using the query builder.
Related
I need to get an element from the database, but I can not get it by the FIND method, since FIND only finds it by the primaryKey and what I need is not by my primaryKey. So I did like this:
$user = Pac::find($request->pac_id);
$element = query()->where('med_cart', $user->pac_id)->get();
$element->med_obs = $request->med_obs;
$element->save(); // error
Now I need to save this element, however, I can not use the SAVE method, as I believe it is fully connected with FIND and FINDORFAIL (if anyone knows, explain to me which methods I can use the SAVE method).
How can I save them the way I did? Or is there some other way to do it?
Because I need to get the element with a data other than the primaryKey and then save it, then I can not use FIND or FINDORFAIL, I think.
The function ->find() returns an Eloquent Model instance and you can then call ->save() on the model instance.
You're using ->get() which returns a Collection.
To update your query (that may target one or more entries) just perform the update statement directly from the QueryBuilder by replacing ->get() with ->update(['med_obs' => $request->med_obs]).
Be aware that when doing this you are now using Fluent queries, instead of eloquent. This means that any logic you may have defined in the boot function of your model is not evaluated.
If you are certain that you only have a single result you can append ->first() to your query, which will return a Model of the first result that matches your ->where clause. You can then call ->save() on it:
$user = Pac::find($request->pac_id);
$element = query()->where('med_cart', $user->pac_id)->first();
$element->med_obs = $request->med_obs;
$element->save();
I dont undertand how these methods work, I'm trying to get last records inserted in my db and for this, I need a query builder so I made y consult with something like this:
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->take(1);
The thing is I'm still getting all records inserted, in these methods take or limit I send the paramether of how many i want to get, and my question is. Why does this happen??
And no, I dont want to use the first() or get() methods these dont work when you do server side processing in a datattable
first() is not return Collection. It returns a Model instance. Maybe you are not clear about Collection vs Model instance.
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->first();
Alternative:
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->get();
// $costo[0]
take(1) or limit(1) just adds limit 1 to the query in builder. You need to call get() to fetch the results and it will return a Collection and you can get its only element by calling first() on it.
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->take(1)->get()->first();
Or you can replace take(1)->get()->first() with just first()
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->first()
first() will add limit 1 and fetch the results and return the only item that's there
Try this
$costo = Costo_promedio::orderBy('created_at','desc')->take(3)->get();
That Will get the last three records from the database assuming that your timestamp is named created_at.
I have a problem with laravel
I want to use a query result in my controller with a if clause to manage what i return to the view.
$res = Chaussures::where('id',$id);
if($res->name=='Adidas'){
return...
}
else {
return...
}
I tried this but it didn't work
You need to execute the query to get the result first. Then you can do whatever you need with the data.
$res=Chaussures::where('id',$id)->first();
Searching for models by ID is such a common task that Laravel has a method called find() to make it easier. This line does the same as the above.
$res=Chaussures::find($id);
I need to understand when/not to use get(); in Laravel 5.
PHP warning: Missing argument 1 for Illuminate\Support\Collection::get()
Google shows me answers to their issue but no one really explains when you should/not use it.
Example:
App\User::first()->timesheets->where('is_completed', true)->get(); // error
App\Timesheet::where('is_completed', true)->get(); // no error
Fix:
App\User::first()->timesheets()->where('is_completed', true)->get(); // no error
Noticed the timesheets() and not timesheets? Could I have a detail explanation for what is going on, please?
I'm coming from a Ruby background and my code is failing as I do not know when to use () or not.
I'll try to describe this as best I can, this () notation after a property returns an instance of a builder, let's take an example on relationships,
Say you have a User model that has a one-to-many relationship with Posts,
If you did it like this:
$user = App\User::first();
$user->posts();
This here will return a relationship instance because you appended the (), now when should you append the ()? you should do it whenever you want to chain other methods on it, for example:
$user->posts()->where('some query here')->first();
Now I will have a the one item I wanted.
And if I needed say all posts I can do this:
$user->posts;
or this
$user->posts()->latest()->get();
$user->posts()->all()->get();
So the key thing here is, whenever you want to chain methods onto an eloquent query use the (), if you just want to retrieve records or access properties directly on those records then do it like this:
$user->posts->title;
Well, ->timesheet returns a collection, where ->timesheet() returns a builder.
On a Collection you can use ->where(), and ->get('fieldname'), but no ->get().
The ->get() method can be used on a builder though, but this will return a collection based on the builder.
Hope this helps.
The 'problem' you are facing is due to the feature of being able to query relations
When accessing a relation like a property, ->timesheets, the query defined in the relationship is executed and the result (in the form of a Collection) is returned to you.
When accessing it like a method, ->timesheets(), the query builder is returned instead of the resulting collection, allowing you to modify the query if you desire. Since it is then a Builder object, you need to call get() to get the actual result, which is not needed in the first case.
When you use ->timesheets you are accessing a variable, which returns the value of it (in this case an instance of Collection).
When you use ->timesheets() you are invoking whatever is assigned to the variable, which in this case returns an instance of Builder.
whilst pascalvgemert's answer does answer your problem regarding Laravel, it does not explain the difference between accessing or invoking a variable.
In simple term
$user = App\User::get();
is used to fetch multiple data from database
rather
$user = App\User::first();
is used to fetch single record from database
I want to set a certain attribute in all the models of a collection.
in plain SQL:
UPDATE table SET att = 'foo' WHERE id in (1,2,3)
the code i have:
$models = MyModel::findMany([1,2,3]);
$models->update(['att'=>'foo']);
taken from here
but doesn't work. I'm getting
Call to undefined method Illuminate\Database\Eloquent\Collection::update()
the only way i have found it's building a query with the query builder but i'd rather avoid that.
You are returning a collection, not keeping the query open to update. Like your example is doing.
$models = MyModel::whereIn('id',[1,2,3]);
$models->update(['att'=>'foo']);
whereIn will query a column in your case id, the second parameter is an array of the ids you want to return, but will not execute the query. The findMany you were using was executing it thus returning a Collection of models.
If you need to get the model to use for something else you can do $collection = $models->get(); and it will return a collection of the models.
If you do not just simply write it on one line like so;
MyModel::whereIn('id',[1,2,3])->update(['att'=>'foo']);
Another option which i do not recommend is using the following;
$models = MyModel::findMany([1,2,3]);
$models->each(function ($item){
$item->update(['att'=>'foo']);
});
This will loop over all the items in the collection and update them individually. But I recommend the whereIn method.
The best solution in one single query is still:
MyModel::whereIn('id',[1,2,3])->update(['att'=>'foo']);
If you already have a collection of models and you want to do a direct update you can use modelKeys() method. Consider that after making this update your $models collection remains outdated and you may need to refresh it:
MyModel::whereIn('id', $models->modelKeys())->update(['att'=>'foo']);
$models = MyModel::findMany($models->modelKeys());
The next example I will not recommend because for every item of your $models collection a new extra query is performed:
$models->each(function ($item) {
$item->update(['att'=>'foo']);
});
or simpler, from Laravel 5.4 you can do $models->each->update(['att'=>'foo']);
However, the last example (and only the last) is good when you want to trigger some model events like saving, saved, updating, updated. Other presented solutions are touching direct the database but models are not waked up.
Just use the following:
MyModel::query()->update([
"att" => "foo"
]);
Be mindful that batch updating models won't fire callback updating and updated events. If you need those to be fired, you have to execute each update separately, for example like so (assuming $models is a collection of models):
$models->each(fn($model) => $model->update(['att'=>'foo']) );